/*
 * Copyright 2005-2009 Roger Kapsi
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

package org.ardverk.collection;

public abstract class AbstractKeyAnalyzer<K> implements KeyAnalyzer<K> {
    
    private static final long serialVersionUID = -20497563720380683L;

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    @Override
    public int compare(K o1, K o2) {
        if (o1 == null) {
            return (o2 == null) ? 0 : -1;
        } else if (o2 == null) {
            return (o1 == null) ? 0 : 1;
        }
        
        return ((Comparable<K>)o1).compareTo(o2);
    }
    
    /** 
     * Returns true if bitIndex is a {@link KeyAnalyzer#OUT_OF_BOUNDS_BIT_KEY}
     */
    static boolean isOutOfBoundsIndex(int bitIndex) {
        return bitIndex == OUT_OF_BOUNDS_BIT_KEY;
    }

    /** 
     * Returns true if bitIndex is a {@link KeyAnalyzer#EQUAL_BIT_KEY}
     */
    static boolean isEqualBitKey(int bitIndex) {
        return bitIndex == EQUAL_BIT_KEY;
    }

    /** 
     * Returns true if bitIndex is a {@link KeyAnalyzer#NULL_BIT_KEY} 
     */
    static boolean isNullBitKey(int bitIndex) {
        return bitIndex == NULL_BIT_KEY;
    }

    /** 
     * Returns true if the given bitIndex is valid. Indices 
     * are considered valid if they're between 0 and 
     * {@link Integer#MAX_VALUE}
     */
    static boolean isValidBitIndex(int bitIndex) {
        return 0 <= bitIndex && bitIndex <= Integer.MAX_VALUE;
    }
}
